GhislainG :
The fridge isn't a solution to motherboard issues unless it overheats and you keep it in there while using it (that would in turn create potential issues like high humidity, etc.)
My first reply on January 2 probably was correct; couldn't you use another GPU? It should be 6-7 years old by now.
Hey Ghislain,
well i got a brand new mainboard. It completely doesn't support the radeon. Must be some incompatibility between the x58 chipset and the amd chipset. Put the old mainboard back together with an i7 cpu i had lying around, and voltage of 12 volt is like 11.8 volt, but sometimes it's 11.9 volts. On the xeon cpu, i had installed before, there was a little black mark on the cpu, between the pins. Yesterday, i ran, with an updated version of furmark, a benchmark and it ran well. Just the gpu temp was almost 100 degrees celsius. So i installed msi afterburner and activated the fan profile. I don't completely trust the complete pc, cause in the past one day it was running fine benchmarking the gpu, and the other day it completely wasn't. But since then, there has come out a cpu patch. So they found a bug in the cpu, which now is resolved. I hadn't installed that patch yesterday, it was still running fine gpu benchmarking it. There is a small chance, there are hackers around the world which dive into that bug and destabilize the pc. Since it's a very old system. You can install, or it will automatically install, when you run iobit care system cleaner. But i must say, the graphics 4k or not, of a displayport to hdmi 2.0 converter, is very nice. Might be an old gpu, but the colours are wonderfull.
So now i got the asrock x58 extreme, with a i7 920 cpu, running at 2.4ghz.
One thing, when finding errors on a mainboard like this, i shouldn't look too much at voltages. It can still run fine with a little lower voltage. The xeon/motherboard power input for the cpu, well it could be some 12 volt links. And if overclocked a lot, maybe the internal resistance it getting more and the 12 volt drops. One psu can handle that better than others.
So for yesterday, gpu and mobo were working right.
Nice day!